多项式加法——MOOC《零基础学习Java语言》

#第五周编程题
多项式加法
注意：
1.多项式全为0，显示0。
2.最高幂次前面不显示加减符号。
3.幂次为1，不显示.
4.系数为1或-1，不显示。

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in = new Scanner(System.in);
		int[] Polynomials = new int[101];
		int maxP=0;
		int sum=0;
		while( true ) {
			int n=in.nextInt();
			int k=in.nextInt();
			Polynomials[n] = k;
			sum += k;
			if(n == 0) {
				break;
			}
		}
		while( true ) {
			int n=in.nextInt();
			int k=in.nextInt();
			Polynomials[n] +=k;
			sum += k;
			if(n == 0) {
				break;
			}
		}
		if(sum == 0) {
			System.out.print(sum);
		}
		for(int i=Polynomials.length-1;i>=0;i--) {
			if(Polynomials[i] != 0 && i != 1) {
				if(Polynomials[i] == 1 || Polynomials[i] == -1) {
					System.out.print("x"+i);
				}
				else {
					System.out.print(Polynomials[i]+"x"+i);
				}
				maxP = i;
				break;
			}
		}
		for(int i=maxP-1;i>=0;i--) {
			if(Polynomials[i] != 0 && i > 1) {
				if(Polynomials[i] == 1 || Polynomials[i] ==-1) {
					if(Polynomials[i] > 0) {
						System.out.print("+");
					}
					else {
						System.out.print("-");
					}
					int v;
					if(Polynomials[i] < 0) {
						v = Polynomials[i] * (-1);
					}
					else {
						v = Polynomials[i] ;
					}
					System.out.print("x"+i);
				}
				else {
					if(Polynomials[i] > 0) {
						System.out.print("+");
					}
					else {
						System.out.print("-");
					}
					int v;
					if(Polynomials[i] < 0) {
						v = Polynomials[i] * (-1);
					}
					else {
						v = Polynomials[i] ;
					}
					System.out.print(v+"x"+i);
				}	
			}
			else if(Polynomials[i] != 0 && i == 1) {
				if(Polynomials[i] == 1 || Polynomials[i] ==-1) {
					if(Polynomials[i] > 0) {
						System.out.print("+");
					}
					else {
						System.out.print("-");
					}
					int v;
					if(Polynomials[i] < 0) {
						v = Polynomials[i] * (-1);
					}
					else {
						v = Polynomials[i] ;
					}
					System.out.print("x");
				}
				else {
					if(Polynomials[i] > 0) {
						System.out.print("+");
					}
					else {
						System.out.print("-");
					}
					int v;
					if(Polynomials[i] < 0) {
						v = Polynomials[i] * (-1);
					}
					else {
						v = Polynomials[i] ;
					}
					System.out.print(v+"x");
				}	
			}
			else if(Polynomials[i] != 0 && i == 0 ) {
				if(Polynomials[i] > 0) {
					System.out.print("+");
				}
				else {
					System.out.print("-");
				}
				int v;
				if(Polynomials[i] < 0) {
					v = Polynomials[i] * (-1);
				}
				else {
					v = Polynomials[i] ;
				}
				System.out.print(v);
			}
		}
	}
}